In brief

Sudden sweat may signal a heart attack

Researchers have found that many heart attack victims (up to a third in one study) don't experience chest pain or anything remotely like the "Hollywood heart attack" in which a person crumples to the floor, gripping his or her chest. In fact, one study reports that for many heart attack sufferers, sudden sweating is the stand-out symptom and the one most likely to take them to a doctor.

Why? According to Catherine J. Ryan, the study's lead investigator and an assistant professor at the College of Nursing at the University of Illinois, Chicago, it may be that breaking out into a sweat for no apparent reason "is one thing that you can't explain away," unlike shortness of breath, nausea, fatigue, and chest pain, which can be chalked up to the flu, a bad night's sleep, a spicy meal, or any number of other things.